5. Radioisotopes
Radioisotopes are isotopes that are radioactive—they spontaneously emit energy (or radiation) when their nucleus breaks down. The term for this process is radioactive decay. When the process involves a change in the number of protons in the nucleus, the atom can change into another element. In one type of radioactive decay, a neutron in the nucleus splits into a proton and an electron. This split decreases the number of neutrons by one and increases the number of protons by one, but since protons and neutrons have approximately the same mass, the mass number stays the same. Since the number of protons changes, the atom becomes a new element.
Carbon-14 has 8 neutrons and 6 protons. When this radioisotope undergoes the radioactive decay process discussed above, it becomes nitrogen-14.
The number of protons in nitrogen-14 is?

The number of proton becomes 7 in nitrogen- 14 because there is one proton increase in the nucleus as a result of radioactive decay. There are 6 number of protons and 8 number of neutron in the nucleus of carbon-14 isotope. when the radioactive decay occurs, there is decrease occur in neutron number by removing one neutron and number of proton increases in the nucleus due to addition of one proton so that's we can say that the number of proton in nitrogen-14 is 7.